<template>
  <div class="type-nav">
    <div class="container">
      <!-- 将商品分类与sort列表放到同一个父级div,利用事件委托鼠标移出,保证鼠标在全部商品分类时也可以被active选中 -->
      <div @mouseleave="mouseleave">
        <!-- 鼠标滑过切换显示与隐藏 -->
        <h2 class="all" @mouseenter="mouseenter">全部商品分类</h2>
        <transition>
          <!-- 当前list显示与隐藏 -->
          <div class="sort" v-show="display">
            <div class="all-sort-list2">
              <!-- 一级 -->
              <div
                class="item"
                v-for="(c1, index) in arr"
                :key="c1.categoryId"
                @click="changeHandler"
              >
                <h3
                  :class="{ acitve: index === currnetIndex }"
                  @mouseenter="change(index)"
                >
                  <a
                    :data-categoryName="c1.categoryName"
                    :data-category1Id="c1.categoryId"
                    >{{ c1.categoryName }}</a
                  >
                </h3>
                <!-- 二级 -->
                <div class="item-list clearfix">
                  <div
                    class="subitem"
                    v-for="c2 in c1.categoryChild"
                    :key="c2.categoryId"
                  >
                    <dl class="fore">
                      <dt>
                        <a
                          :data-categoryName="c2.categoryName"
                          :data-category2Id="c2.categoryId"
                          >{{ c2.categoryName }}</a
                        >
                      </dt>
                      <dd>
                        <!-- 三级 -->
                        <em v-for="c3 in c2.categoryChild" :key="c3.categoryId">
                          <a
                            :data-categoryName="c3.categoryName"
                            :data-category3Id="c3.categoryId"
                            >{{ c3.categoryName }}</a
                          >
                        </em>
                      </dd>
                    </dl>
                  </div>
                </div>
              </div>
            </div>
          </div>
        </transition>
      </div>

      <nav class="nav">
        <a href="###">服装城</a>
        <a href="###">美妆馆</a>
        <a href="###">尚品汇超市</a>
        <a href="###">全球购</a>
        <a href="###">闪购</a>
        <a href="###">团购</a>
        <a href="###">有趣</a>
        <a href="###">秒杀</a>
      </nav>
    </div>
  </div>
</template>

<script>
import throttle from "lodash/throttle";
import { mapState } from "vuex";
export default {
  name: "TypeNav",
  data() {
    return {
      // active默认值为-1不选中状态
      currnetIndex: -1,
      //定义显示状态
      display: true,
    };
  },
  //计算属性
  computed: {
    //获取vuex中的home小仓库列表数据
    ...mapState({
      arr: (state) => state.home.categoryArr,
    }),
  },
  methods: {
    //lodash/throttle节流动态设置active类名
    change: throttle(function (index) {
      this.currnetIndex = index;
    }, 20),
    //数据委派
    changeHandler({ target }) {
      //dataset 获取标签中的data-标记
      let { categoryname, category1id, category2id, category3id } =
        target.dataset;

      if (categoryname) {
        //只要可以进判断,证明点击的是a标签
        let path = { name: "search", query: { categoryName: categoryname } };

        //category1id
        if (category1id) {
          path.query.category1Id = category1id;

          //category2id
        } else if (category2id) {
          path.query.category2Id = category2id;

          //category3id
        } else {
          path.query.category3Id = category3id;
        }

        // 判断params内是否有title,有证明有params就添加
        if (this.$route.params.title) {
          path.params = this.$route.params;
        }
        //插入路径
        this.$router.push(path);
      }
    },
    //鼠标滑入
    mouseenter() {
      if (this.$route.path !== "/home") this.display = true;
    },
    //鼠标移出
    mouseleave() {
      if (this.$route.path !== "/home") this.display = false;
      this.currnetIndex = -1;
    },
  },
  //挂载钩子
  mounted() {
    //只要路由为home就显示
    if (this.$route.path !== "/home") this.display = false;
  },
};
</script>

<style scoped lang="less">
.type-nav {
  border-bottom: 2px solid #e1251b;

  .container {
    width: 1200px;
    margin: 0 auto;
    display: flex;
    position: relative;

    .all {
      width: 210px;
      height: 45px;
      background-color: #e1251b;
      line-height: 45px;
      text-align: center;
      color: #fff;
      font-size: 14px;
      font-weight: bold;
    }

    .nav {
      a {
        height: 45px;
        margin: 0 22px;
        line-height: 45px;
        font-size: 16px;
        color: #333;
      }
    }

    .sort {
      position: absolute;
      left: 0;
      top: 45px;
      width: 210px;
      height: 461px;
      position: absolute;
      background: #fafafa;
      z-index: 999;

      .all-sort-list2 {
        .item {
          h3 {
            line-height: 30px;
            font-size: 14px;
            font-weight: 400;
            overflow: hidden;
            padding: 0 20px;
            margin: 0;

            a {
              color: #333;
            }
            &.acitve {
              background: yellowgreen;
            }
          }

          .item-list {
            display: none;
            position: absolute;
            width: 734px;
            min-height: 460px;
            background: #f7f7f7;
            left: 210px;
            border: 1px solid #ddd;
            top: 0;
            z-index: 9999 !important;

            .subitem {
              float: left;
              width: 650px;
              padding: 0 4px 0 8px;

              dl {
                border-top: 1px solid #eee;
                padding: 6px 0;
                overflow: hidden;
                zoom: 1;

                &.fore {
                  border-top: 0;
                }

                dt {
                  float: left;
                  width: 54px;
                  line-height: 22px;
                  text-align: right;
                  padding: 3px 6px 0 0;
                  font-weight: 700;
                }

                dd {
                  float: left;
                  width: 415px;
                  padding: 3px 0 0;
                  overflow: hidden;

                  em {
                    float: left;
                    height: 14px;
                    line-height: 14px;
                    padding: 0 8px;
                    margin-top: 5px;
                    border-left: 1px solid #ccc;
                  }
                }
              }
            }
          }

          &:hover {
            .item-list {
              display: block;
            }
          }
        }
      }
    }
    .v-enter {
      height: 0px;
      background-color: #333;
    }

    .v-enter-active {
      transition: all 0.5s linear;
    }

    .v-enter-to {
      height: 461px;
      background-color: rgb(75, 215, 43);
    }
  }
}
</style>